Receiver for systems of submarine signaling.



110. 852,760. I PATENTEDMAY 7,190"7. "L. I. BLAKE.

'REGEIVER FOR SYSTEMS 0F SUBMARINB SIGNALING.

APPLICATION FILED JAN. 29, 190'! 2 SHEBTFSBBBT 1'.

A -1r l I G I lji 29mm; 1 5]wuewtoz v I I gffto g" I PATEN TED MAY 7, 1907.

' v L. I. BLAKE. REGBIVER FOR SYSTEMS 0P SUBMARINE SIGNALING;

: APPLIOAVTIOHVPIL'BD JAE-29, 1901.

m V l i awuewfoz;

- LUOIEN I. BLAKE, OF BOSTON, MASSA I citizen of the IUNITED: sTA ns- PATENT oF roE.

CHUSETTS, ASSIGNOR TO SUBMARINE SIGNAL COMPANY, or BOSTON, MASSACHUSETTS, A CORPORATION or- MAINE.

To all whom it man concern:

Be itknown that I, LUOIEN I. BLAKE, a

United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented or discovered certain new and useful Improvements in Receivers for Systems of Submarine Signaling,

.of which the following is a specification, ref-- erence being had to the drawings accompanying and forming part of the same. i

As an understanding of the nature of the invention upon which my present application is based, involves a knowledge of the phenomenon of resonance, the following statement of well recognized principles is apposlte.

The fundamental principle of acoustic resonance is reflection. In any portion of a gaseous medium which is -isolated ,by which term as used herein is meant wholly or partially confined by boundary walls of any suit- I able material differing in its physical properthe cavity itself,

tions of the principle medium without ties from the inclosed 1nediu m,a reflection occurs at the surfaces of the boundary walls, of any acoustic disturbance present in that medium. This reflected. disturbance will travel back and forth between the walls or bpundaries to produce a tone of definite pltch, dependent upon the volume and shape oftlie medium inclosed. The chamber "or cavity formed by the boundary walls is called a resonance cavity. The method of exciting a glven medium to resonance is immaterial.

It may be effected by sound vibrations brought into it from an outside and remote source, vor by vibrations originating within Itis not necessary hereinafter described, or in general, that the cavity be entirely surrounded by reflecting walls, for an opening may be left in the latter through or at-which vibrationsfmay be imparted to the medium Within thecavlty, and another through which the regular periodic vibrations of the medium affected may be communicated to any other the boundaries of the cavity. The function of the resonance cavity thus becomes a reinforcerj of sound, whether received or produced. Y I v In all aerial sound producers resonance chambers are the essential elements for giv-' Specification of Letters Patent. Application filed January 29,1907. Serial No. 354,626.

to end ofthe pipe, and this is in any of the applica RECEIVER FOR SYSTEMS OF SUBMARINE SIGNALING.

Patented ma 7, 1907.

ing intensity of sound. Their action is exemplified in the case of or an pipes and Whis s tles. In these the column of air inclosed within the walls of the resonance chamber is set into regular periodic or harmonic vibration at the einbouchure by either the socalled 'flute mouth-piece or a reed. When the length of the air column is great in comparison with its other dimensions as in the 'case of a pipe, the pitch is controlled by the reed is set in vibration by the air or steam Illlpinging upon its unconfined edge, and the air or steam column sustains and reinforces these vibrations, controlling their rate and consequently the pitch of the tone if the reedbe not too stiff. In either case the free vibration of the column within the pipe or chamber is the essential source of sound.

j In connection with the consideration of called the free the action or effect of these resonance cavities, it is important to bear in mind the distinction between the freevibration of the inclosed medium and the forced ,vibrations which occur in consonant materials excited by any source of sound. In the phenomenon of resonance, one definite pitch-is conspicuous or natural for each'given set of conditions, while in the case of consonance, sounds of any pitch are reinforced. In the former the sizeand shape of the mass of confined medium control in determining the pitch, the character of the containing walls, within certain limitshereinafter more fully explained, being immaterial are capable of reflecting the disturbances;

provided they while in the latter, the physical character of the consonant body is the controlling consideration, size and shape being-immaterial.

I have discovered and practically demonstrated that under proper conditions a liquid medium may be readily. brought into sonorous resonance-with a tone of given pitch, and that an isolated portion of liquid medium possesses, according to its dimensions, a cer tain musical pitch of its own. If, under such conditions, harmonic vibrationsbe set up within a body of liquid the latter may be caused to strongly reinforce these vibrations and consequently intensify the sound produced by them. Such a li uid masswill also reinforce sounds delivered into it from a distance, whereby weak tones will be rendered more audible, so that it may, therefore, be utilized, like an aerial resonator, both for the production and reception of sounds. Availing myself of this discovery, I have employed liquid resonators in systems of submarine signaling with'resultsof a highly useful and novel character.

The desirability of securing the advanta es of resonance for intensifying sound, eit er produced for transmission or received from a distant source, in the art of submarine signaling, has been recognized by those skilled in the art. As an abstract proposition it is in fact, self suggestive from analoous results in the application of the same road principle in the case of wind instruments, whistles, and in general those devices in which a sound of given itch is reinforced b a resonating body 0 air or gas No usefulor practical application of the principle to submarine signaling, however, has ever been made, so far as I am aware, and for the reason, which my discovery has now rendered apparent, that conditions essential to the attainment of the resonance of iso lated bodies of liquid, have not been recognized or secured in any a paratus that has been designed or propose "for use either as producers or receivers of sound under water.

In all wind instruments and other devices in which the resonance of a confined or iso- 'lated body of air is utilized, the resonating medium is of such'a higlllily compressible na-' ture in comparison wit the materials ordinarily constituting its boundaries, that the latter may be of almost any 'gid material, such as wood, paper or very thin metal. If, however, the medium which it is desired. to set into resonance be a liquid, which is practically incompressible as compared with any gas, the rhythmic changes of pressure within it which corres nd to sound, exert exceed-. ingly powerfu total pressures over the boundary walls of the "chamber or cavity containing the liquid, according to the laws of hydrostatics. Such pressures, as is wellknown, may bend and even burst walls of ordinary strength. Therefore, if liquid resonators be constructed without due regard to the effect upon the retaining walls of these yariations of hydrostatic pressure, they present conditions which actually remove the elements upon which reflection depends, but

the effect of which is negligible when the ma if submer ed in water, be operate rounding them, it will medium is an easily compressible gas, such as air. It is for this reason. that a water column in an ordinary organ pipe does not produce resonance. This may be conclusively demonstrated by the following experiments: If a pipe 4 inches in cross sectional area and several feet lon be made of hard metal, say i of an inch Erick, which would produce very much greater rigidity than would be required in any ordinary tone-producing instrument, and provided with an embouchure similar to that of an organ pipg, fit 0 y a jet of water in the same produce a tone manner as an or an pipe is operated by air. It will be found, owever, that the tone fproduced has a pitch wholly independent 0 the thus showing that the water column is not set in resonance. The reason for this, as I have found, is that the rigidity of the walls is not sufiicient to withstand the variations in hydrostatic pressure and thereby reflect the regular periodic or harmonic vibrations imparted to the mass of liquid within the pipe. If the walls of the pipe yield, then any change in the pressure originating at the embouchure of the inclosed liquid will be instantly relieved at that point, and therefore no change in pressure will be propagated through the pipe to undergo reflection, and thereby to produce resonance. In .short, the liquid column remains quiescent at its normal pressure, and takes no part whatever in the production or reinforcement of sound. If the samepipe, however, be made of very hard and tough steel, with walls even more unyielding than the practically incompressible water sur- 7 e found to roduce, when operated b a water jet in t e same way a tone of de nite pitch that varies with the length of the pipe, thus proving that the liquid mass within the same is brought into resonance. To ,convey an idea of what is re uired in securing the proper character of inc osing walls for a liquid resonator, it may be stated that air is over twenty thousand times more compressible than water; and water over-sixty times more compressible than hard steel, so that to secure the requ 1- I site rigidit of the walls in the case of a liquld resonator have found it necessary to build them up by shrinking very tough steel tubes upon one another.

length of. the pipe,

plying the principle of the discovery 0 mon to both forms of instrument.

ings, Figure 1 is a viewin same. recelver 1n which the lnventlon trated the application of the principle of resonance' to both sound producers and sound receivers for submarine systems, but have confined the more specific claims to the former. and to features of novelty that'are com- In the present application the claims are directed to those features of novelty which'more particularly distinguish the application of the principle tosound receivers. I have, however,- as a more convenient illustration of the principle, shown in the accompanying draw ngs, the sound. producer of the application referred to. f

Referring now to' the accompanying drawelevation of the sound producer, showing the means for 0 erating the same.- Fig. 2 isa longitudinal cross-section of the operative parts of the Fig. 3 is a sectional View of the sound upon which my present application is based,- is embodied.

Referring to Figs. 1 and 2, Aisa cylinder of steel. It is shown as closed at one end and with the other open end beveled on of about degrees to sharp edges; I It is-not necessary that the cylinder be closed, but, as

will. be understood, tosecure the same free period of vibration of a column of liquid within it, an 0 en cylinder must be of double the length. l h practice I have found that'for good results a cylinder designed for a given an annular orifice L i proximity to the annular orifice L,

the other.

pitch and having a bore of 3 inches in diameter and 11 inches long should have walls 1% inches in thickness of very hard tough steel built up by shrink] B, B the heads 0, D, head C is secured are side bars connecting of a rigid frame. 'In. the or integral with it is cast, an inlet, through 1s introduced by a ipe G from any suitablesource capable 'of delivering itat a high pressure. l/Vithin the chamber E is a spider H carrying a plate "K- of slightly smaller. diameter than an opening in the end of the chamber, andwhich therefore leaves )referably of about 1,

of an inch in width. n'the head D is a circular opening with threaded. walls withwhich corresponding threadson the exterior of the cyhnder A engage. By this means'the cyhnder is rigidly supported with its beveled edge in pro erposition relative to the annular orifice. and with the capability of adjustment with respect thereto; The cylinder A isadjusted. to bring its 'edgein close and is submerged at any sounds or signals are to be produced. Water an angle 'ng several tubes, one over access of the water its threaded connection desired point where the under presifire, preferably from 1.25 to 200 pounds, is hen supplied to the chamber E, and issuing therefrom in the form. of an 'annu-' lar jet impinges upon the edges and beveled end of the cylinder A, with the result that the harmonic or regular periodic vibrations are set up in the column of water within the cylinder. These vibrations, owing to the unyielding character "ofthe boundaries of the chamber or cavity in which the column of water is contained are reflected back and forth from the walls and the column is therefore set 1n sonorous resonance.

dependent upon the dimensions of the chamber or cavity-within the cylinderA. I have ound that sounds thus produced will becarried to great distances through water and may be detected and rendered audible by suitable sound receiving instruments the more readily because of theirdistinctive Inn-- By interrupting or varylng sical character. the pressure 'of the water supplied to the chamber E, or by-deflecting the jet issuing from the orifice in said chamber, distinctive- Such an apparatus will produce a tone of definite pitch slgnals, according to any prearranged code,

'mziy be sent by this device. a n

Fig. 3 which illustrates the device for receiving sound S represents a portion of the skin of-a steel vessel, which is selected for urposes of illustration. To the inner surace of the skin-is secured, as by means of bolts P passing through flan es at its end, a

steel cyhnder M of the same c aracter as that described in connection with Figs. 1 and 2. The op osite or inner end of the cylinder M is closed by a head N of corresponding thickness, the edges of W 'ch are threaded to enga e with threads in the inner surface of the cyfindera A small orifice V is formed in thehead N and an ordinary microphonic trans-' mitter T is secured over the same or placed at any point at which it will be operated by the resonance of the column of water contained in the cylinder M. microphone with an ordinary telephone receiver. A smallopening R maybe drilled through the ships into the cylinder M,- but this 1s not necessary for reasons previously described, as sounds water would be transmitted throught e Wall of the ship' to the water column in the cylinder M, even'were no passage of communication present. The head N, by means of With the cylinder M, may be adjusted to varythe dimensions of the chamber within the cylinder, and thus control the pitch of the resonant cavity in order to tune it to any desired source'of .sound. In this device the column of water through the ships wall or the opening R.

Wires 0, 0, connect the skin in order to permit entering either coming throu h the The sound thus intensified operates the microphone, which produces in the telephone receiveran audible sound.

While I have described the invention by reference to a specific form of apparatus, it

is evident that its construction may be In general, the sound re ceiver maybe submerged at any selected station or placed in a tank attached to the walls of a vessel so that by means of the apparatus signals may be transmitted from the shore to a vessel, or conversely, or between vessels within the limits of practical transmission.

What I claim as my invention is:

1. A sound receiver for submarine signaling systems, com rising in combination a receptacle with wa ls capable of withstanding the variations of hydrostatic pressure accom panying regular periodic vibrations in a body of liquid contained therein, and reflecting the same to roduce resonance, and a sensitive device a apted to be acted upon by such vibrations, as set forth.

2. A sound receiver for submarine signaling systems comprising in combination a receptacle secured to the side of a vessel and greatly varied.

, having walls capable of withstanding the variations of hydrostatic pressure acc0mpan n'g regular periodic vibrations in a body of liquid contained therein, and a sensitive device in position to be affected by such vibrations, as set forth.

3. The combination of a liquid resonator consisting of a receptacle with rigid walls capable of reflecting regular periodic or harmonic vibrations set up in a body of liquid contained within the same, an a microhonic sensitive device, secured over an orice in the end of the receptacle through which the vibrations are caused to act upon the sensitive device, as set forth.

4. The combination of a liquid resonator consisting of a receptacle with rigid walls capable of reflecting regular periodic or harmonic vibrations set up in a contained within the same, and secured over an o ening in the side of a vessel, and a micro onic sensitive device secured over an ori ce in the end of the receptacle through which the vibrations are caused-to act upon the sensitive device, as set forth.

5. A sound receiver for submarine signalin systems,'comprising in combination a hollow cylinder Wltll walls capable of with standing the variations in hy rostatic pressure accompanying the vibrations imparts to a body of liquid contained therein and reflecting the same to produce resonance, a

head adjustable in said cylinder to vary the dimensions of the chamber within the cylinder,

and-a sensitive device in position to be affected by the vibrations of the body of liquid, as set forth.

. LUCIEN I. BLAKE.

Witnesses:

MACALLASTER: Moons, J. CONVERSE GRAY.

body of liquid 

